Mt. Haleakala Volcano

This is the view looking over the lava dome atop Maui's Mt. Haleakala. This is so high up that the roadways have some warning signs aboutdriving in the clouds The elevation at the summit of the caldera is so high -- one of the highest-altitude volcanos on Earth -- that the air is thin and even the grass looks funny. (E.g., see the shot of these cows.) There are many adaptations at the crater's edge, including one of the most amazing (and rarest) plants on earth, the Silversword.

The lava dome itself, with its eerie purple and earth tones, lava-flow dunes, lunar-like cinder cones and legendary tricks of light, is a setting sometimes used by astronauts for training; this certainly does look like the surface of Mars or the moon.